chore: add code_coverage command to justfile

.justfile

@@ -1,12 +1,15 @@
 default:
   just --list
 
-check_semver:
-  cd 01.workspace/heave && cargo semver-checks --baseline-rev origin/next --verbose
-
 extract_devlog date:
   git log --pretty=format:"%ad|%s" --date=short --since="{{date}} 00:00" | extract-devlog.sh
 
+check_semver:
+  cd 01.workspace/heave && cargo semver-checks --baseline-rev origin/next --verbose
+
+code_coverage:
+  cd 01.workspace && cargo llvm-cov clean && cargo llvm-cov --show-missing-lines
+
 sync_remotes:
   git push codeberg.org next
   git push github.com next